Infratentorial supracerebellar approach for pineal region tumors versus suboccipital transtentorial approach: our surgical and technical considerations

Introduction: Many approaches were described to resect tumors in the pineal region, being he Infratentorial Supracerebellar (ITSC) and Suboccipital Transtentorial (SOTT) routes the most commonly used. However, there are no uniform indications for choose the best approach for each case. The objective of this study is to describe a feasible method to select patients for these two approaches.

Methods: Forty-two patients were divided in 3 groups: Group 1 (25 patients, ITSC approach); Group 2 (15 patients, SOTT approach); and Group 3 (2 patients, combined approach). The decision for an approach was done taking in concern the angle between a perpendicular line in relation to the sagital plane, beginning in the torcula, and a line parallel to the tentorium of the tentorial surface in sagital MRI view. The ITSC route was chosen when the angle was higher than 45 grades and the SOTT route when the angle was lesser than 45 grades. The combined approach was chosen when the tumor had supra and infratentorial extension.

Results: In Group 1 (25 patients), the mean age was 42.4 years (2–73 years), composed by 13 women (52%). All patients obtained a total resection. Visual impairment after surgery was observed in 1 patient, hydrocephalus in 1 patient with meningitis, and 1 surgical bed hematoma. The Group 2 (15 patients) was composed by 9 (60%) women, with a mean age of 26,5 years (21–39 years). Thirteen patients had their tumor totally resected. Only one case presented visual impairment and transient contralateral hemiesthesia. In both groups, the histological diagnosis was heterogeneous, (the most common were meningiomas and from pineal parenchyma). In Group 3, composed by 2 women, both patients had meningioma as histologic diagnosis. There was no surgical mortality.

Discussion: To our best knowledge, there are studies that only describes the different angles of tentorium. This is the first study that describes the application of this anatomical landmark in the choice of best approach to resection of tumors of pineal region. We have low prevalence of complications, and it is a safe, simple and applicable method to guide the surgeons to choose a route to operate pathologies in the pineal region and avoid technical difficulties during the tumor removal.

Conclusion: The anatomical landmark based on the angle between the tentorial surface and horizontal plan is a feasible instrument to define the ideal individual approach to pineal region tumors.

No conflict of interest has been declared by the author(s).